Cleaning compositions, such as detergents, shampoos, and cleaners include one or more surfactants or soaps to allow for the removal of organic material form a substrate in an aqueous environment. The surfactants are sold as concentrates that must generally be melted for processing into final commercial products.
The cleaning compositions also contain other ingredients, such as hydrophobically modified polymers, and amphiphilic compounds such as hydrotropes, which provide beneficial product and end-use properties.
Hydrotropes are added to isotropic liquid detergents to help incorporate higher levels of surfactants and to help prevent phase separation of the detergent. The use of hydrotropes in isotropic liquid detergents is described in U.S. Pat. No. 5,719,117.
Hydrophobically modified water-soluble polymers are used in laundry and cleaning compositions, and are useful for soil release properties and in preventing soil redeposition. U.S. Pat. No. 5,723,434 describes the use of a hydrophilic polymer backbone having a hydrophobic pendant group in isotropic liquid detergents. The polymer helps improve the clarity of the isotropic liquid detergent. U.S. Patent Publication No. 2003/0162679 describes hydrophobically modified polymers as being useful in increasing the dissolution rates of surfactants into aqueous systems, especially from single-dose tablets, pouches, and sachets. Furthermore, these polymers are useful in suspending hydrophobic soils in autodish and hard surface cleaning applications. The hydrophobically modified polymers also act as corrosion inhibitors for aluminum in a variety of applications.
U.S. Pat. No. 5,789,511 describes the synthesis of styrene or substituted styrene monomer with a carboxylated monomer to produce a hydrophobically modified water-soluble polymer. These polymers provide good soil release properties and are useful in cleaning compositions for fabrics and hard surfaces.
U.S. Pat. No. 6,337,313 describes the synthesis and use of hydrophobically modified polymers with hydrophilic backbones and at least one hydrophobic moiety in a textile manufacturing or treating process.
U.S. Pat. No. 5,886,076 describes a cleaning composition having an alcohol ethoxylate surfactant and 1 to 10 percent of a polymer of styrene and a carboxylate monomer. The polymer provides good soil release properties.
The cited references describe the combination of hydrophobically modified water-soluble polymers or hydrotropes with surfactants in the context of laundry and other cleaning compositions. These ingredients play key roles in the effectiveness of the detergent of cleaning composition. None of the references describe any synergy to a concentrated blend of a hydrophobically modified polymer or hydrotrope with a surfactant.
Surprisingly it has now been found that hydrophobically modified water-soluble polymers and hydrotropes effectively change the physical properties of concentrated surfactants, making the surfactants easier and faster to process into useful end-products. The modified concentrated surfactant composition shows an increase in the rate of surfactant dissolution, and a lower melting point of the surfactant, improving the ease of handling.